Oil-based food products including chocolates are usually solid under storage environment and are characterized by readily melting in the mouth. Chocolates are, as just described, characterized by having both good heat resistance and melting feeling in the mouth.
These characteristics of the chocolate is mainly affected by an oil and fat blended therein. The oil and fat that is most suitable for chocolates is cacao butter. However, because the cacao butter is expensive, cacao butter substitutes prepared from another vegetable oil and fat are often used for the oil and fat in chocolates as well. The cacao butter substitute used as the oil and fat in chocolates is also referred to as hard butter. The hard butter is in general classified into a tempering type and non-tempering type.
Tempering type hard butter contains, as a major component, a symmetric triglyceride which is contained in the cacao butter in a large amount. Hence, it is easy to substitute the tempering type hard butter for the cacao butter and the tempering type hard butter can be mixed to use with the cacao butter in any blending formulation. Further, the tempering type hard butter exhibits sharp melting feeling in the mouth. And when chocolates were produced by use of this tempering type hard butter, tempering is, as in the case of cacao butter, required to be carried out.
On the other hand, the non-tempering type hard butter has melting properties similar to those of the cacao butter but has completely different oils and fats structure. Hence, the non-tempering type hard butter is poorly compatible with the cacao butter. However, the non-tempering type hard butter is cheaper pricewise, as compared with the cacao butter, and does not require cumbersome tempering, which provides ease of handling. Thus, the non-tempering type hard butter is widely used in the field of confectionery production bread making. The non-tempering type hard butter is roughly divided into a lauric acid type and non-lauric type.
Among the non-tempering type hard butter, lauric acid type hard butter contains lauric acid as a major constituent fatty acid. Typically, one obtained by hydrogenating a high melting point fraction (palm kernel stearin) to extremely hydrogenate, which high melting point fraction is obtained by fractionating palm kernel oil, is known. The melting properties of this kind of hard butter are extremely sharp. Yet, because the compatibility thereof with cacao butter is extremely poor, the blending ratio of the cacao butter needs to be set to as low as possible. Hence, chocolates in which the lauric acid type hard butter is used are poor in cocoa flavor. In addition, there is a problem in that, when used in confectionery or bread containing a relatively high amount of water, chocolates in which the lauric acid type hard butter is used generate soap smell if storage conditions are poor.
Among the non-tempering type hard butter, non-lauric type hard butter is also referred to as trans acid type hard butter. Typically, known are one obtained by subjecting liquid oil such as low melting point palm olein or soy bean oil to isomerization hydrogenation; and a high melting point fraction or intermediate melting point fraction obtained by, as necessary, further fractionating the one that has been subjected to the isomerization hydrogenation. The melting properties of non-lauric type hard butter lacks sharpness slightly, as compared with the lauric acid type, whereas the compatibility thereof with the cacao butter is better than that of the lauric acid type and thus more cacao butter can be blended, as compared with the case of the lauric acid type. However, because the non-lauric type hard butter contains a large amount of trans fatty acids, used thereof has been avoided since adverse health effects of the trans fatty acids came to be recognized.
Due to these kinds of the circumstances, the reduction of the trans fatty acids in the non-lauric type hard butter is sought.
As non-lauric type hard butter in which trans fatty acids are reduced, hard butter obtained by mixing, at a specific ration, an oil and fat obtained by hydrogenating an oil and fat containing a specific amount of SUS type triglyceride and an oil and fat containing a specific amount of SSU type triglyceride (see Patent Document 1) and hard butter in which an oil and fat obtained by hydrogenating specific transesterified oil is blended in a specific amount (see Patent Document 2) are known. In these hard butter, the trans fatty acids are reduced to some extent, as compared with conventional trans acid type hard butter. Yet, it could not be said that the reduction was sufficient.
Further, the melting properties of the trans acid type hard butter depend on trans fatty acids contained therein. There is thus a problem in that if the trans fatty acids are reduced, good heat resistance and melting feeling in the mouth of chocolates are impaired.
From the above, development of non-tempering type hard butter that has a low trans fatty acid content and is a non-lauric type is demanded, which non-tempering type hard butter makes it possible to produce oil-based food products including chocolates with good heat resistance and melting feeling in the mouth.